Upconverting nanoparticles are phosphors that absorb light at a first wavelength and emit light at a shorter wavelength in an Anti-Stokes emission process. Many upconverting nanoparticles absorb light in the near IR range and emit light in the visible region. Upconverting nanoparticles have been synthesized using host lattices such as LaF3, YF3, Y2O3, LaPO3, NaYF4 codoped with trivalent rare earth ions such as Yb+3, Er3+, and Tm+3. The rare earth lanthanide ions doped in crystal centers of the lattice act as absorber ions and emitter ions.
In the prior art the use of upconverting nanoparticles is typically associated with putting the upconverting nanoparticles in a biological material or system to facilitate detection of a component and/or imaging as the Anti-Stokes emission of upconverting nanoparticles has good photostability under prolonged emission excitation, the emission of the upconverting nanoparticles is a wavelength(s) that is distinguishable from natural fluorescence in biological materials and the upconverting nanoparticles have low toxicity.
Other applications of upconverting nanoparticles include product and/or brand authentication, improved efficiency of LED lamps, and renewable energy applications. In renewable energy applications, optical nano-materials have the ability to better utilize the full spectrum of solar radiation, which results in an enhanced photovoltaic energy efficiency, and more effective use of solar energy, for example.
Scintillator based detection systems are widely used in nuclear and particle physics and in commercial imaging devices such as medical imaging and non-destructive evaluation devices. Scintillator based detection systems have a scintillator material which has the property of luminescence namely the ability to produce light when excited by ionizing radiation. The detection system also has a sensor that receives the light produced by the scintillation material. Photomultiplier tubes are exemplary of commonly used sensors. The sensor may be physically positioned so that the light produced by the scintillator material can strike the sensor or the scintillator material may be coupled to the sensor via a device such as a light guide.
The scintillator based detection devices of the prior art are known to have a shortcoming in that the wavelength of light that maximizes transmission in the scintillator material is not the optimum wavelength of sensitivity for the commonly used sensors. Accordingly, the sensitivity and efficiency of the detection system is less than optimum.
Accordingly, there is a need for a scintillator based detection system with improved matching of scintillator light transmission and sensitivity of the sensor.